Recirculating chemical-sanitizing washing machine

ABSTRACT

A method for operating a recirculating chemical-sanitizing dishwasher includes filling a wash tank of the dishwasher with water, and performing a first cycle of washing by circulating the water through a wash chamber of the dishwasher. A partial drain is performed of a first amount of water from the wash tank, and new water (for example, rinse water) is added to the wash tank for a second amount of water approximately equal to the first amount. A second cycle of washing is performed by circulating the water through the wash chamber of the dishwasher.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims the benefit of U.S. Provisional PatentApplication No. 63/328,200, filed Apr. 6, 2022, which is incorporated byreference herein in its entirety.

TECHNICAL FIELD

This application relates generally to washing machines and moreparticularly to a method and apparatus for recirculating water in awashing machine such as a dishwasher.

BACKGROUND

A dishwasher, also referred to as a warewasher or warewashing machine,is a machine for automatically cleaning articles, such as dishes, trays,laboratory equipment, dinnerware, and kitchenware. A common domesticdishwasher is an undercounter unit intended to be installed under akitchen counter. Other types of dishwasher include industrial orcommercial dishwashers for use in restaurants, hotels, and othercommercial establishments with food services.

Common types of dishwashers include dump-and-fill type machines andrecirculating type machines. Dump-and-fill type machines draincompletely between washing and rinsing cycles, whereas recirculatingtype machines reuse wash water from cycle to cycle. Dump-and-fill typemachines typically use a longer duration for cleaning and inherentlywaste water and energy, and recirculating type machines can leaveresidual detergent or soil and may require additional heating andmachine complexity to maintain water temperature.

What is needed is an improved dishwasher that provides cleaner dishes,reduced cycle times and minimal additional heating or machinecomplexity.

SUMMARY

A system and method for operating a recirculating chemical-sanitizingdishwasher includes filling a wash tank of the dishwasher with water,and performing a first cycle of washing by circulating the water througha wash chamber of the dishwasher. A partial drain is performed of afirst amount of water from the bottom of the wash tank, and new water isinjected into the wash tank in a second amount of water approximatelyequal to the first amount. A second cycle of washing is performed bycirculating the water through the wash chamber of the dishwasher.

In one example, the first amount of water is approximately 20 to 30percent of capacity of the wash tank. In some examples, the mini drainis performed several times over several cycles, and the wash tank issubsequently completely drained and refilled before proceeding with anext cycle.

This summary is an overview of some of the teachings of the presentapplication and not intended to be an exclusive or exhaustive treatmentof the present subject matter. Further details about the present subjectmatter are found in the detailed description and appended claims. Thescope of the present invention is defined by the appended claims andtheir legal equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate generally, by way of example, variousembodiments discussed in the present document. The drawings are forillustrative purposes only and may not be to scale.

FIG. 1A illustrates one example of a recirculating wash dish machine.

FIG. 1B illustrates one example of a dump-and-fill dish machine

FIGS. 2A-2C illustrate a recirculating chemical-sanitizing dishwasher,according to various embodiments of the present subject matter.

FIG. 3 is a schematic diagram illustrating a recirculatingchemical-sanitizing dishwasher, according to various embodiments of thepresent subject matter.

FIG. 4 illustrates a user menu for operation of machine setpoints for arecirculating chemical-sanitizing dishwasher, according to variousembodiments of the present subject matter.

FIG. 5 illustrates a graphical diagram for washing sequence step for arecirculating chemical-sanitizing dishwasher, according to variousembodiments of the present subject matter.

FIG. 6 is a flow chart illustrating a method for operating arecirculating chemical-sanitizing dishwasher, according to variousembodiments of the present subject matter.

DETAILED DESCRIPTION

The following detailed description of the present subject matter refersto subject matter in the accompanying drawings which show, by way ofillustration, specific aspects and embodiments in which the presentsubject matter may be practiced. These embodiments are described insufficient detail to enable those skilled in the art to practice thepresent subject matter. References to “an”, “one”, or “various”embodiments in this disclosure are not necessarily to the sameembodiment, and such references contemplate more than one embodiment.The scope of the present invention is defined by the appended claims,along with the full scope of legal equivalents to which such claims areentitled.

This application discusses, among other things, a chemical-sanitizingdish machine that utilizes a recirculating wash to save water, energy,and chemistry while maintaining proper wash water heat by draining asmall portion of wash water prior to the rinse step (referred to hereinas a partial drain or a mini-drain), running frequent cycles where thetank fully drains, and utilizing a small tank size.

The present system, apparatus and method provides a low-temperature,chemical sanitizing dish machine utilizing digital controls that allowoperational modes that save water and energy and decrease total washcycle time, to replace the current dump-and-fill low-temp dish machine,which is inherently wasteful in terms of water, energy, and chemistry.The present system enables running the machine in a recirculating modeto reuse wash water from cycle to cycle while maintaining washtemperature without a dedicated heat source, including preserving washtemperature by partially draining a portion of wash water prior to rinseintroduction.

According to various embodiments, a recirculating system is providedwhere the tank is not fully drained every cycle, and the rinse isintroduced through a separate set of rinse nozzles from a freshwatersource. The present system maintains wash tank temp by utilizing asmaller tank size (approximately 2 gallons in an embodiment) anddisplaces a large amount of this with rinse water (approximately 0.75gallons/rack in an embodiment). Additionally, a small portion of coolerwash water is drained (a partial drain or mini drain) from the bottom ofthe tank prior to the rinse being introduced. In some embodiments, thepartial drain may be performed from other portions of the tank. In someembodiments, the tank is fully drained approximately once every 5 cyclesto refresh the tank and manage food soil loads. Since these refreshcycles will introduce higher water volumes into the machine that need tobe concentrated with additional chemistry, the present system mayintroduce a detergent boost on the cycle immediately following the tankrefresh. This boost automatically lengthens the detergent dispense timeby an amount proportional to the extra time that the fill valve is openduring the refresh.

Various embodiments provide a system for operating a recirculatingchemical-sanitizing dishwasher. The system includes a dishwasher with awash tank, wash chamber and drain. A wash tank of the dishwasher isfilled with water, and a first cycle of washing is performed bycirculating the water through a wash chamber of the dishwasher. Apartial drain is performed of a first amount of water from the bottom ofthe wash tank, and new water is injected into the wash tank in a secondamount of water approximately equal to the first amount. A second cycleof washing is performed by circulating the water through the washchamber of the dishwasher. In one example, the first amount of water isapproximately 20 to 30 percent of capacity of the wash tank. In someexamples, the partial drain is performed several times over severalcycles, and the wash tank is subsequently completely drained andrefilled before proceeding with a next cycle.

FIGS. 1A-1B illustrate examples of dump-and-fill and recirculatingwashing machines. FIG. 1A illustrates an example of a recirculating dishmachine type with rotating rinse arms, rotating wash arms, a wash tankstrainer, an overflow pipe, a pump inlet strainer, a wash pump, and adrain. The recirculating dish machine performs a recirculating cleaningsequence with fresh water rinse, including a wash step and a rinse step.In the wash step, the wash pump recirculates wash water with detergentfrom the wash tank through wash arms and over dishes. The wash water isreused from cycle to cycle. In the rinse step, incoming fresh water atline pressure is injected with rinse aid and sanitizer if applicable,and sprayed through the rinse arms over the dishes. Typically, for hightemperature recirculating machines, heaters are required to maintainwash temperature from cycle to cycle, and rinse water from a previouscycle is collected in the wash tank and displaces a like amount down thedrain.

FIG. 1B illustrates an example of a dump-and-fill dish machine type withincoming water, rotating wash and rinse arms, a pump inlet strainer, asump, a drain stopper/overflow pipe, a drain pan strainer, a wash pumpand a drain. The dump-and-fill dish machine performs a cleaning sequenceincluding a wash step, a drain step, a fill step and a rinse step. Inthe wash step, the wash pump recirculates wash water with detergent fromthe wash tank through the wash arms and over the dishes. In the drainstep, water and soils are drained completely from the machine. In thefill step, the machine fills with fresh water and is dosed with rinseaid and sanitizer. In the rinse step, the pump recirculates rinse waterfrom the tank through the wash arms and over the dishes. Rinse waterfrom the previous cycle remains in the machine and is used as wash waterfor the next cycle. Typically for low temperature chemical sanitizingdump-and-fill machines incoming hot water each cycle maintains arelatively warm temperature from approximately 120 to 140 F.

Benefits of the recirculating machine of FIG. 1A include a faster cycletime because there is no drain and fill in the middle of a cycle, nocarry-over of detergent and/or soils to dishes at the end of a cyclesince wash water and rinse water are completely separated, and separatemechanical systems for wash and rinse allowing for optimization for bothwash and rinse. Drawbacks of the recirculating machine of FIG. 1Ainclude recirculating dirty wash water over dishes which requiresperiodic stopping of operating to remove soils and draining andrefilling the tank, low incoming water pressor reduces the quality ofthe rinse, low temperature of incoming water can cause low rinsetemperatures as the booster heater cannot recover fast enough tomaintain temperature, and relatively high complexity.

Benefits of the dump-and-fill machine of FIG. 1B include that soils aredrained from the machine after each wash sequence, the pumped rinsethrough the wash arms adds to cleaning action, chlorine from the rinsein the wash step can improve cleaning, and effective rinse action is notreliant on incoming water pressure. Drawbacks of the dump-and-fillmachine of FIG. 1B include residual detergent or soils on dishes afterthe rinse step if not completely drained after the wash step, incomingwater temperature controls temperature of the rinse water, and a longduration between wash cycles reduces temperature of wash water.

FIGS. 2A-2C illustrate a recirculating chemical-sanitizing dishwasher,according to various embodiments of the present subject matter. FIG. 2Aillustrates advantages of the recirculating chemical-sanitizingdishwasher of the present subject matter when compared to traditionaldump-and-fill and recirculating machines. The recirculatingchemical-sanitizing dishwasher combines benefits of both traditionaldump-and-fill and recirculating machines without the drawbacks listedabove. The present recirculating chemical-sanitizing dishwasherrecirculates water with frequent dumps or partial drains to maintaintemperature and lower food soil resulting in cleaner dishes. Thus, thepresent recirculating chemical-sanitizing dishwasher provides a simpledesign that is easy to service, is affordable, can handle heavy foodsoil loads, does not require a heater, lowers water consumption, usesshorter cycle times, and utilizes a fresh water rinse. Detergentchemistries may be dispensed in various ways according to variousembodiments. In various embodiments, the present subject matter issuited for solid detergent chemistries. In various embodiments, thepresent subject matter is suited for liquid detergent chemistries. Invarious embodiments, an amount of injected detergent is proportional tothe amount of the injected water, to maintain a level of detergent inthe water. In one embodiment, the amount of injected detergent is scaledto the amount of water injected.

FIG. 2B illustrates an overview of an embodiment of the recirculatingchemical-sanitizing dishwasher of the present subject matter. Thedishwasher includes a display, an input/output (I/O) board, a powersupply, swing-out doors, and dispensing and accessory connections. Thepresent dishwasher provides a low-temperature innovation using a novelcontrol system. The control system includes a digital I/O board withflexible operation and enhanced features, improved troubleshooting, andenabling digital strategy. The present recirculating chemical-sanitizingdishwasher further includes an improved display with a simple userinterface. In addition, the present recirculating chemical-sanitizingdishwasher provides for improved machine operation including partialdrains that reduce water usage by over 25%, result in a 30% reduction incycle time, improved startup and shutdown sequences, and an automateddelime sequence. The recirculating chemical-sanitizing dishwasherincludes a redesigned control head with swing-out doors for easieraccess, a large footprint for easy service, and fewer components thattraditional recirculating machines.

FIG. 2C illustrates further details of an embodiment of therecirculating chemical-sanitizing dishwasher of the present subjectmatter. The recirculating chemical-sanitizing dishwasher includes a newdispensing system with diaphragm pumps to replace traditional squeezetubes, support for both liquid and solid detergent chemistries, andprovides for warning and/or alarms. The recirculatingchemical-sanitizing dishwasher includes an improved inlet plumbingsystem including flexible “jiffy” hoses with swivel fittings providingfor improved field service and flexible installation. The recirculatingchemical-sanitizing dishwasher also includes a fresh water rinse systemincluding a halo design to eliminate moving parts, the fresh water rinsedecreasing detergent carryover between cycles or steps.

FIG. 3 is a schematic diagram illustrating a recirculatingchemical-sanitizing dishwasher, according to various embodiments of thepresent subject matter. The recirculating chemical-sanitizing dishwasherincludes a drain connection A, an electrical connection B, and a waterinlet C, in various embodiments. According to various embodiments, thepartial drain allows the old, colder water to be controllably releasedper cycle, so the machine stays full as the new water cycles into themachine. In some embodiments, the machine performs a complete dump ofall water every 5 cycles in which case the full drain cycle will drainall water from the tank.

FIG. 4 illustrates a user menu for operation of machine setpoints for arecirculating chemical-sanitizing dishwasher, according to variousembodiments of the present subject matter. From a service menu, a usermay navigate to a machine setpoints menu to adjust machine parameters.In various embodiments, fill time adjusts the amount of time the machinefills on startup and following a full drain of the tank. The partialdrain time is the amount of time the drain is open during an exemplary(non-full) drain cycle, in various embodiments. According to variousembodiments, water drained during the partial drain is approximatelyequal to the amount of water added during the rinse step. In variousembodiments, the amount of water drained during a partial drain may bevaried.

FIG. 5 illustrates a graphical diagram for washing sequence step for arecirculating chemical-sanitizing dishwasher, according to variousembodiments of the present subject matter. Unlike prior wash machines,the present recirculating chemical-sanitizing dishwasher operates as arecirculating machine with frequent full tank drains. Wash water ismaintained in the tank from cycle to cycle until a full drain cycle isrun, in various embodiments. In some embodiments, full drain frequencydefaults to every 5 cycles, but is adjustable from every cycle to every10^(th) cycle. In various embodiments, a freshwater rinse is introducedinto the machine via the incoming water line (from approximately 15-25pounds per square inch or psi). A short partial drain (at a default timeof 1.4 seconds, which is adjustable) occurs following the wash stepduring exemplary cycles, in various embodiments. This partial drainflushes a portion of dirty wash tank water which is then replaced by theincoming freshwater rinse, improving the machine performance withoutrequiring additional heating, in various embodiments.

FIG. 6 is a flow chart illustrating a method for operating arecirculating chemical-sanitizing dishwasher, according to variousembodiments of the present subject matter. The method 600 for operatinga recirculating chemical-sanitizing dishwasher includes filling a washtank of the dishwasher with water at step 602, and performing a firstcycle of washing by circulating the water through a wash chamber of thedishwasher at step 604. At step 606, a partial drain is performed of afirst amount of water from the bottom of the wash tank, and new water isinjected into the wash tank in a second amount of water approximatelyequal to the first amount at step 608. At step 610, a second cycle ofwashing is performed by circulating the water through the wash chamberof the dishwasher.

In various embodiments, adding additional water in a second amountincludes adding rinse water. In various embodiments, adding additionalwater includes adding water directly to the wash tank. Persons of skillin the art will appreciate that a variety of ways to add water to thetank may be employed without departing from the scope of the presentsubject matter.

According to various embodiments, the first amount of water isapproximately 20 to 30 percent of capacity of the wash tank. In someembodiments, the method further includes performing a partial drain ofthe first amount of water from the bottom of the wash tank, injectingnew water into the wash tank in the second amount of water approximatelyequal to the first amount, and performing a third cycle of washing bycirculating the water through the wash chamber of the dishwasher. Themethod also includes performing a partial drain of the first amount ofwater from the bottom of the wash tank, injecting new water into thewash tank in the second amount of water approximately equal to the firstamount, and performing a fourth cycle of washing by circulating thewater through the wash chamber of the dishwasher, in variousembodiments. In some embodiments, the method further includes performinga full drain of a third amount of water from the bottom of the washtank, the third amount approximately equal to capacity of the wash tank,injecting new water into the wash tank in a fourth amount of waterapproximately equal to the third amount, and performing a fifth cycle ofwashing by circulating the water through the wash chamber of thedishwasher.

In various embodiments, the present subject matter provides a washingsequence including:

-   -   a. a wash cycle where wash water containing detergent in the        wash tank is recirculated via wash pump through the wash        chamber;    -   b. A partial drain function where the drain ball is opened to        drain a set volume (less than the entire volume) from the tank;    -   c. A full drain function where the drain ball is opened to drain        the entire volume from the tank; and    -   d. A rinse drain function where the fill valve opens and        supplies fresh water (dosed with rinse aid and sanitizer) at        line pressure from house water supply equal in volume to the        partial drain (or the tank volume in the case of a full drain).        The water in the tank is not recirculated through the chamber        via the wash pump in this step.

Those of skill in the art upon reading and understanding the presentsubject matter will appreciate that the order of steps and quantity ofeach step may vary without departing from the scope of the presentsubject matter.

In this application, a “dishwasher”, which can also be referred to as adish machine, a warewasher or a warewashing machine, includes any typeof wash machine that can use detergent for cleaning and/or sanitizingpurposes. One example includes an undercounter dishwasher for washingdinnerware, flatware, pots and pans, cutlery, flatware, glasses,kitchenware, serving pans, trays, and so on. Commercial dishwashingequipment examples can also use the present subject matter. A dishwasherincludes a washing tub formed by interior walls and a door of thedishwasher. In an example of the undercounter kitchen dishwasher, thedoor rotates up to about 90 degrees about a horizontal axis to switchbetween a fully closed state and to a fully open state. The door has aninterior side and an exterior side that are both substantially verticalwhen the door is fully closed and substantially horizontal when the dooris fully open.

A “cleaning cycle” can include other periods, such as one or more of awashing period, a rinsing period, and a drying period, depending onsettings made by a user of the dishwasher. The door is opened at leastonce between two consecutive cleaning cycles to allow loading of thedishes and/or other objects to be cleaned and unloading of the cleaneddishes and/or other objects. “Cleaning” can include cleaning only,sanitizing only, or cleaning and sanitizing, depending on, for example,whether the solid detergent blocks are capable of cleaning only,sanitizing only, or cleaning and sanitizing. A “washing period” includesa period or operational mode that is intended for a cleaning mixtureformed by water and detergent to be applied to the dishes and/or otherobjects. A “rinsing period” includes a period or operational mode thatis intended for water, or water and a chemical rinsing aid and/or achemical sanitizer, to be applied to the dishes and/or other objects.Some dishwashers (e.g., commercial dishwashers) may include a rinsingperiod that is primarily for sanitizing through heat and/or chemicalmeans. A “drying period” includes a period or operational mode that isintended for the cleaned dishes and/or other objects to be dried by airflow and/or heat, without additional water and/or detergent applied. Thedishwasher usually allows the user to choose whether to include thedrying period in the cleaning cycle because the user can open thedishwasher door to allow the washed and rinsed dishes to dry naturallyor remove the washed and rinsed dishes to another place for drying.

A batch of objects to be cleaned (for example, dishes) can be loadedinto a tub of the dishwasher, typically including racks and utensilholders, to be cleaned in a cleaning cycle that include washing andrinsing periods. During the washing period, a cleaning mixture formed bywater and dishwasher detergent is sprayed into the loaded tub to blastthe dishes. Typically, the cleaning mixture is then drained before therinsing period starts. During the rinsing period, water is sprayed intothe washing chamber to remove residue of the cleaning mixture. After therinsing period complete with the rinsing water being drained, the dishescan optionally be dried using air and/or heat during a drying period. Adishwasher may have various user-selectable settings for each cleaningcycle. The settings may define, for example, time, temperature, andrepetition of each of the washing, rinsing, and drying period. Thesetting may also allow the user to choose which periods to include(e.g., rinsing only, drying only, rinsing and drying, or washing andrinsing without drying).

Application in a dishwasher is discussed as an example, but not alimitation, for the present subject matter. The present system for canbe applied in any washing machine that sprays water that can bepartially drained during a cleaning cycle.

Some non-limiting examples (Examples 1-5) of the present subject matterare provided as follows:

In Example 1, a method for operating a recirculating chemical-sanitizingdishwasher may include providing a tank of water in a wash tank of thedishwasher, using the tank of water for a first wash process of thedishwasher, partially draining a first amount of water from the tank ofwater in the wash tank, adding additional water to the wash tank in asecond amount approximately equal to the first amount, thereby creatinga partially refreshed tank of water, wherein the additional water doesnot include the water drained from the tank, and using the partiallyrefreshed tank of water for another wash process of the dishwasher. Invarious embodiments the steps of partially draining, adding additionalwater, and using the partially refreshed tank of water can be repeated anumber of times, such as 1 to 5 times. In various embodiments, themethod includes fully draining the wash tank. In various embodiments,the method includes adding new water to refill the wash tank. In variousembodiments, the method includes using a rinse process for addingadditional water. In various embodiments, the method includes using arinse process for adding new water.

In Example 2, the subject matter of Example 1 may optionally beconfigured to further include the first amount of water mayapproximately 20 to 30 percent of capacity of the wash tank.

In Example 3, the subject matter of any one or any combination ofExamples 1 and 2 may optionally be configured to further includepartially draining the first amount of water from the partiallyrefreshed tank of water, injecting new water into the wash tank in thesecond amount approximately equal to the first amount, thereby creatinga second partially refreshed tank of water, and circulating the secondpartially refreshed tank of water through the wash chamber of thedishwasher.

In Example 4, the subject matter of Example 3 may optionally beconfigured to further include partially draining the first amount ofwater from the second partially refreshed tank of water, injecting newwater into the wash tank in the second amount approximately equal to thefirst amount, thereby creating a third partially refreshed tank ofwater, and circulating the third partially refreshed tank of waterthrough the wash chamber of the dishwasher.

In Example 5, the subject matter of Example 4 may optionally beconfigured to further include draining a third amount of water from thethird partially refreshed tank of water, the third amount approximatelyequal to capacity of the wash tank, injecting new water into the washtank in a fourth amount of water approximately equal to the thirdamount, thereby creating a fully refreshed tank of water, andcirculating the fully refreshed tank of water through the wash chamberof the dishwasher.

In Example 6, the subject matter of Example 1 may further includedispensing detergent in an amount relating to the amount of fresh waterinjected into the wash tank.

In Example 7, the subject matter of Example 6 may optionally beconfigured where the dispensing is performed using a solid detergentchemistry.

In Example 8, the subject matter of Example 6 may optionally beconfigured where the dispensing is performed using a liquid detergentchemistry.

In Example 9, the subject matter of Example 6 may optionally beconfigured where the amount of detergent is proportional to the amountof new water injected into the wash tank.

In Example 10, the subject matter of Example 1 may optionally beconfigured where adding the additional water includes using rinse water.

This application is intended to cover adaptations or variations of thepresent subject matter. It is to be understood that the abovedescription is intended to be illustrative, and not restrictive. Thescope of the present invention should be determined with reference tothe appended claims, along with the full scope of legal equivalents towhich such claims are entitled.

What is claimed is:
 1. A method for operating a dishwasher, the methodcomprising: providing a tank of water in a wash tank of the dishwasher;using the tank of water for a first wash process of the dishwasher;partially draining a first amount of water from the tank of water in thewash tank; adding additional water to the wash tank in a second amountapproximately equal to the first amount, thereby creating a partiallyrefreshed tank of water, wherein the additional water does not includethe water drained from the tank; and using the partially refreshed tankof water for another wash process of the dishwasher.
 2. The method ofclaim 1, wherein the first amount of water is approximately 20 to 30percent of capacity of the wash tank.
 3. The method of claim 1, furthercomprising: partially draining the first amount of water from thepartially refreshed tank of water; injecting new water into the washtank in the second amount approximately equal to the first amount,thereby creating a second partially refreshed tank of water; andcirculating the second partially refreshed tank of water through a washchamber of the dishwasher.
 4. The method of claim 3, further comprising:partially draining the first amount of water from the second partiallyrefreshed tank of water; injecting new water into the wash tank in thesecond amount approximately equal to the first amount, thereby creatinga third partially refreshed tank of water; and circulating the thirdpartially refreshed tank of water through the wash chamber of thedishwasher.
 5. The method of claim 4, further comprising: draining athird amount of water from the third partially refreshed tank of water,the third amount approximately equal to capacity of the wash tank;injecting new water into the wash tank in a fourth amount of waterapproximately equal to the third amount, thereby creating a fullyrefreshed tank of water; and circulating the fully refreshed tank ofwater through the wash chamber of the dishwasher.
 6. The method of claim1, further comprising: dispensing detergent in an amount relating to theamount of fresh water injected into the wash tank.
 7. The method ofclaim 6, wherein the dispensing is performed using a solid detergentchemistry.
 8. The method of claim 6, wherein the dispensing is performedusing a liquid detergent chemistry.
 9. The method of claim 6, whereinthe amount of detergent is proportional to the amount of new waterinjected into the wash tank.
 10. The method of claim 1, wherein addingthe additional water includes using rinse water.
 11. A method foroperating a dishwasher including a wash tank, a wash pump and a washchamber, the method comprising: performing a wash cycle where wash watercontaining detergent in the wash tank is recirculated via the wash pumpthrough the wash chamber; performing a partial drain function where adrain ball is opened to drain a set volume less than an entire volumefrom the wash tank; and performing a rinse drain function includingopening a fill valve to supply fresh water dosed with rinse aid anddetergent at line pressure from a water supply approximately equal tothe set volume.
 12. The method of claim 11, wherein the wash water inthe wash tank is not subsequently recirculated through the wash chambervia the wash pump.
 13. The method of claim 11, further comprising:performing a full drain function where the drain ball is opened to drainan entire volume from the wash tank.
 14. The method of claim 11, whereinthe set volume is approximately 20 percent of capacity of the wash tank.15. The method of claim 11, wherein the set volume is approximately 30percent of capacity of the wash tank.
 16. The method of claim 11,wherein supplying fresh water dosed with rinse aid and detergentincludes dispensing rinse aid and detergent in amounts relating to theset volume of fresh water supplied into the wash tank during the rinsedrain function.
 17. The method of claim 16, wherein the dispensing isperformed using a solid detergent chemistry.
 18. The method of claim 16,wherein the dispensing is performed using a liquid detergent chemistry.19. The method of claim 16, wherein the dispensing is performed using aliquid rinse aid chemistry.
 20. The method of claim 16, wherein thedispensing is performed using a solid rinse aid chemistry.